Powered road vehicle comprising a replaceable rear body mounting

ABSTRACT

A powered road vehicle, namely a passenger car having a permissible maximum laden weight of 3.5 tons or a lorry having a permissible maximum laden weight of 5 tons, comprises: a base vehicle having a load-transferring bottom structure which includes a vehicle body bottom and/or a carriage. The bottom structure is provided with a front axle and at least one rear axle. The base vehicle also includes a vehicle body supported on the bottom structure, the rear part of the vehicle body having side walls. A replaceable rear body mounting upwardly joins the side walls and is supported directly on the bottom structure in a load-transferring manner. The rear body mounting is releasably locked in a main coupler of the base vehicle, and the main coupler is supported directly on the bottom structure in a load-transferring manner. The rear body mounting is also fixed to a separate aligning coupler arranged at a distance from the main coupler. The rear body mounting is adapted to engage the aligning coupler in a pre-alignment position, and to be lowered from the pre-alignment position into a locking position at the main coupler. The main coupler is arranged both to provide main coupling of the rear body mounting to prevent displacement and rotation thereof, and to support a semi-trailer so that vertical loads and trailing forces are transferred.

The invention relates to a powered road vehicle comprising areplaceable, and thus variable, rear body mounting.

Road vehicles normally have a permanent body structure associated withthe vehicle to allow the transport of commodities and/or people, forexample. These vehicles are provided with non-variable bodies.

A further category of vehicles provides so-called swap bodies, i.e. therear bodies of such vehicles can be replaced by other bodies within arelatively short time, these bodies being designed in different ways forvarious applications. Such interchangeable bodies exist in increasingnumbers in the field of big commercial vehicles, because they allow aparked body to be loaded or unloaded independently of the presence ofthe powered carriage.

Vehicles comprising variable rear bodies have been known primarily fromthe field of trucks and commercial vehicles, mainly in relation to swapbodies, i.e. bodies that can be placed easily onto an existing carriage(including the drive engine and the driver's cab) and can also beremoved easily therefrom. The purpose of such a system is to enable apowered unit (carriage including the drive engine and driver's cab) toutilise a plurality of variable bodies. In this manner, a parkedvariable body may be loaded and unloaded while the powered unit istransporting other variable bodies. This organisation saves time as thepowered unit is in use during the loading and unloading of the body, andit saves capital as it is not necessary to purchase a separate poweredunit for each variable body. Moreover, the prior art vehicle bodymountings exclusively constitute mountings that do not communicate withthe inner space of the vehicle.

The use of variable rear bodies in the form of swap bodies is very easyin the context of said types of trucks and commercial vehicles sincethese vehicles have an extremely stable carriage (including the engineand driver's cab) on which the variable bodies can be mounted easily.There is no interference with a body structure such as that of a car orlight commercial vehicle.

Conversely, the use of variable bodies for smaller vehicles has beenrealised only in the form of studies and single pieces. While theconcept as such is obvious and logical, its implementation causesconsiderable problems with respect both to technical design andfinancial aspects.

An object of the invention is to provide a technical solution enablingthe use of variable rear bodies for smaller powered road vehicles,preferably the size of cars and smaller commercial vehicles.

Another object of the invention is that the variable rear bodies shouldnot only be transportable in the form of swap bodies, but they should beable to form part of the vehicle body when mounted thereon, such thatthe inner space of a variable rear body mounting may form a spaceintegral with the driver's and/or passengers' space of the base vehicle.

The prior art has already provided basic technical solutions also inthis field allowing the conversion of a normal car into a cabriolet orcoupe, for example. In the prior art, however, the variable bodies aregenerally mounted on the body structure of the base vehicle, preferablyon the side and roof portions thereof, which have to be reinforcedaccordingly or supplemented by support structures.

The intrinsic serious drawback of such designs is that they requirecompletely different body designs--as compared to conventional vehiclebodies--for transferring and receiving the forces of added conversionbodies. The relatively soft car body structure can either carry onlylight body mountings, or when designed to accommodate heavier bodymountings, it requires solid reinforcements which are costly and heavy.

One of several prior art examples is represented by the Nissan Exasports car of 1986, in which the rear body mounting behind the targaroll bar can be replaced such as to produce a coupe variation, acabriolet variation and a sports combination. However, theseinterchangeable rear bodies represent only extremely light, smallmountings of minor utility and variability with respect to the vehicleas a whole.

The most sophisticated and advanced solution--in terms of bothconstruction and system--for light road vehicles having variable carbodies has been presented by Mercedes-Benz at the Geneva Car Fair 1995in the form of a concept car called Vario Research Car (VRC). Thisconcept allows the car to be converted by replacing the upper rear bodystructure at both sides toward the front, up to the B-column, while theroof is replaced completely up to the frame of the front windshield.This variability has a substantial impact on the entire vehicle concept,and allows the base vehicle to be converted from an estate car into a2-door saloon car, a pick-up, and a cabriolet, respectively. Thevariable car bodies can be formed relatively light by applyingsophisticated technology and expensive lightweight construction. On theother hand, the variations also show that this concept relatesexclusively to a passenger car while heavier vehicle bodies cannot beemployed, one reason being that a considerable part of the forces fromthe variable bodies is transferred to the frame of the front windshield.

Regarding heavier rear body mountings, indispensable for industrialapplications, a disadvantage resides in that the load is received in thearea of the rear axle in a plane above the wheel casings through areinforced lateral structure of the vehicle body. This constructionalsolution again allows only light variable body mountings to be used, asthe forces from the body mountings have to be transferred to the bottomstructure through lengthy paths.

Summarising the drawbacks of the prior art constructions of powered roadvehicles having variable rear body mountings in the field of light roadvehicles (aimed at by the solution according to the invention), thestatic and dynamic forces arising from the mass of the variable vehiclebody mounting are received at a place relatively high above the centreof gravity of the base vehicle, said forces are transferred to thevehicle body structure which may be reinforced, and/or the variable rearbody mountings can only be relatively light. Variability is thereforeconsiderably restricted, in particular with respect to variations forindustrial applications which frequently have to be relatively heavy andvoluminous to allow bigger loads or bulky commodities to be transportedin order for the vehicle to be profitable.

According to the invention, these drawbacks are obviated by the basicconcept that the forces arising from the variable rear body (mass,dynamic forces resulting from movements of the vehicle and the like) arelargely received at the lowermost point of the carriage (depending onthe vehicle type and construction), i.e. at the load-transferring bottomstructure from which the wheels are suspended, while only theconsiderably smaller forces resulting from other operations, such asinserting and removing, centering, sealing and securing of the variablerear body with respect to the base vehicle, are transferred entirely orpartly to the vehicle body structure of the base vehicle.

The road vehicle contemplated by the invention preferably comprises atypical passenger car such as a saloon car, a coupe, a cabriolet, anestate car, a van or minivan, an off-road or cross-country vehicle, or aminibus. The invention covers cars of this type up to a permissiblemaximum laden weight of 3.5 tons, in particular if they do not have aseparate carriage but a self-supporting car body bottom. Moreover, smalltrucks, in particular closed box-shaped vehicles, having a maximum ladenweight of 5 tons may be designed in accordance with the invention. Thesame applies to road vehicles according to the invention in which theload-transferring bottom structure, from which the wheels are suspended,is represented by a separate carriage, having two longitudinal beams,for example, or a carriage in combination with a vehicle body bottomstructure participating in the transfer of the load.

Each road vehicle according to the invention comprises an autonomousbase vehicle including a powered drive unit and a load-transferringbottom structure which consists of a vehicle body bottom and/or carriageand is equipped with a front axle and a single rear axle or twin rearaxles.

Following usual terminology in the field of vehicle engineering, theterms "front axle" and "rear axle" are not meant to define anycontinuous axle components but the front and rear wheels, the associatedsuspension and spring systems, and the imaginary geometric axes aboutwhich the respective wheels rotate during straight travel of thevehicle.

The body bottom structure, from which the wheels are suspended throughassociated wheel suspensions, is constituted by the bottom structure ofa self-supporting vehicle body and/or carriage, depending on the type ofvehicle, and supports a vehicle body mounting that forms an individualcab or double cab comprising a space for the driver and, as the case maybe, a space behind the driver's seat. This space may be open toward therear, or closed by a wall which may be detachable. The rear bodymounting, preferably the part thereof immediately adjacent to theB-column, further comprises side walls protruding vertically from thebottom structure and surrounding the rear part of the base vehicle onboth longitudinal sides and on the rear side, as seen in the normaltravelling direction of the vehicle. The side walls may join the frontbody through transitional body portions. The rear part of the basevehicle, above the bottom structure, is largely open towards the top.

In a basic version of the road vehicle according to the invention, areplaceable rear body mounting is arranged above the side walls andupwardly covers the aforementioned open rear part of the base vehicle,the longitudinal sides and the rear side such that the part of the rearbody mounting disposed above the side walls joins the body of the basevehicle.

According to the invention, the rear body mounting--as well as any otherrear body mounting substitutable for the rear body mounting of the basicversion--is supported directly, in a load-transferring manner, on thebottom structure and is (a) releasably locked to the base vehiclethrough a main coupler which is directly supported on the bottomstructure in a load-transferring manner, and (b) positively held by aseparate aligning coupler arranged at a distance from the main coupler.

The main coupler according to the invention is designed as a main lockto secure the position of the rear body mounting with respect to thebase vehicle and to prevent rotation of the rear body mounting.Therefore, the rear body mounting in use is positively locked throughthe main coupler (cooperating with a mating coupler formed or fixed atthe rear body mounting) to accommodate all the dynamic main forcesacting on the rear body mounting during driving, independently of anyload being present or absent on the rear body, and the main couplertransfers these dynamic main forces directly to the load-transferringbottom structure of the body, from which the wheels of the vehicle aresuspended. The load forces resulting from the own weight and additionalload weights of the respective rear body mounting are primarilyintroduced directly into the load-transferring bottom structure. Totransfer these load forces, the rear body mounting may be supported onthe main coupler in a load-transferring manner. Additionally oralternatively, the rear body mounting may be seated on the bottomstructure, directly or through interposed support means, such as frames,support blocks, or rollers and the like. Preferably, such support meanshave limited resiliency so that they are squashed toward the bottomstructure when the rear body mounting is locked to the main coupler. Theoverall design of the main coupler and the support means (if provided)is such that the body of the base vehicle is at most charged withsecondary forces transferred by the respective rear body mounting.

Further according to the invention, the rear body mounting is positivelyfixed and locked to the base vehicle through an aligning couplerarranged at a distance from the main coupler. The aligning couplercooperates with a mating alignment assembly arranged on the rear bodymounting, the aligning coupler and mating alignment assembly beingdesigned such that when the rear body mounting is to be fitted thealignment assembly of the rear body mounting can be positively insertedinto the aligning coupler of the base vehicle and positively pre-lockedin a pre-alignment position and then positively guided and lowered, in alinear or pivoting movement, from the pre-alignment position to a finalposition until the mating coupler of the rear body mounting is receivedand locked in the main coupler of the base vehicle. Accordingly, themain coupler is designed to enable the mating coupler of the rear bodymounting to be linked to the main coupler when the rear body mounting islowered or pivoted downward.

Therefore, owing to the aligning coupler, the rear body mounting can beplaced on the base vehicle and pre-aligned so as to be placed onto themain coupler of the base vehicle in a unitary displacing movementallowing the rear body mounting to be locked through the main couplerand to be positively held additionally on the base vehicle by thealigning coupler at a distance from the main coupler. However, since atleast the major part of the forces acting on the rear body mounting(consisting of the own weight of the rear body mounting, the loadreceived by the rear body mounting unless transferred directly to thebottom structure through support means of the rear body mounting, and inparticular the dynamic forces as exerted on the rear body mountingduring the drive states of the powered vehicle) is transferred to thebottom structure through the main coupler, only secondary forces need tobe transferred to the base vehicle through the aligning coupler. Thisallows the aligning elements to be implemented in the form of relativelylight components with respect to their weight and rigidity.

Moreover, the main coupler and aligning coupler may be designed suchthat the rear body mounting can be removed in the inverse order of theinstallation steps. Hence, when the rear body mounting is to be removed,the main coupler is unlocked, the rear body mounting is lifted orpivoted from the main coupler, elevated to the pre-alignment position inthe alignment assembly, and then pulled out therefrom.

According to an embodiment of the invention, the main coupler may beeven formed and designed such that it is further adapted to transferloads and tractive forces when supporting a semi-trailer, allowing thebase vehicle of the invention to be selectively used as a tractionvehicle of a semi-trailer, thus considerably increasing the versatilityof the base vehicle. In this arrangement, the main coupler according tothe invention is designed and fixed to the bottom structure such thatthe vertical loads of the trailer in all driving states and the tractiveforces required to pull and push the trailer in all driving states canbe transferred to the bottom structure and, thus, to the base vehicle.Depending on the design of the main coupler, vertical trailer loads inthe range of 1,000 to 15,000 N and horizontal pulling/pushing forces of5,000 to 50,000 N as required for trailing operations of the basevehicle can be transferred to the bottom structure.

The coupler joint required for the trailer coupler may be embodied inthe form of an intermediate adapter that can be locked to the maincoupler of the invention to fix the position of the intermediate adapterand to prevent it from rotating, as in the case of a rear body mounting;to this end, the side of the intermediate adapter facing the maincoupler mates the main coupler.

All the rear body mountings according to the invention are designed tobe locked to the base vehicle in the same manner cooperating with themain coupler on the one hand and the aligning coupler on the other hand.The types of interchangeable rear body mountings in particular comprisebox-like mountings closed on all sides; estate mountings glazed on thelateral (longitudinal) and rear sides, open or closed at the front end,lacking or including seats, preferably including a rear door, andpossibly including a separate luggage boot; roller roof mountingsincluding integrated seats; open trough mountings; caravan mountings;cassette mountings combining a plurality of modules into a structuralunit; and the like.

Interchangeable rear body mountings according to the invention may beprovided with a lower part arranged to be fitted between the side wallsand comprising a preferably completely closed bottom, on which themating coupler (cooperating with the main coupler) and theload-transferring support means (if any) are arranged to support therear body mounting on the bottom structure of the base vehicle. To thisend, the bottom of the rear body mounting is formed and/or reinforcedsuch as to be self-supporting.

Further, the interchangeable rear body mountings, or at least a sub-setthereof, are provided with shoulders seated on the longitudinal sidewalls and possibly on the rear wall. If the rear body mounting isdesigned to lengthen the interior space of the vehicle, said shouldersmay be formed as sealing shoulders. The sealing shoulders only serve totransfer secondary forces, as far as required to achieve the desiredsealing function even when the body of the base vehicle and the rearbody mounting itself rock during travelling. This relief of the bodystructure of the base vehicle can be achieved by the feature that atleast the rear body support means arranged on the body of the basevehicle to transfer vertical downward forces, including means forsupporting aligning couplers on the vehicle body, are arranged to yield,preferably in a resilient or elastic manner, so that the major part ofthe vertical main forces is transferred directly to the bottomstructure.

The upstanding rear wall of the base vehicle may be realised as a fixedwall. Preferably, however, the rear wall is arranged as a pivotable rearflap or door. This rear door may be comprised of a single door leafpivotable up and down by means of a lower hinge. In a preferredembodiment, the rear door comprises two door leaves that may be pulledaround the corners formed by the longitudinal and rear side walls, andpivoted about hinges arranged in the longitudinal side walls at adistance from the rear ends thereof. This arrangement allows the wholewidth between the longitudinal side walls to be utilised in dimensioningthe width of the rear body mountings.

The aligning coupler may be provided in the form of one centralstructural unit arranged in the longitudinal axis of the vehicle, or inthe form of two or more aligning coupler units arranged, at a distancefrom each other, on the body of the base vehicle and/or on the bottomstructure thereof. The entry portion of the aligning coupler may beprovided with a conically converging alignment mouth piece, into which acomplementary projection of the rear body mounting may be inserted in apivoted or linearly lifted position, such as to direct the rear bodymounting until the pre-alignment position is obtained where the rearbody mounting enters the aligning coupler. Conversely, the alignmentmouth piece may be arranged on the rear body mounting, and theprojection may be arranged at the aligning coupler.

Further, the aligning coupler is equipped with a guiding mechanism toguide the rear body mounting from its pre-alignment position into thefinal position, in which the rear body mounting is engaged in the maincoupler, by pivoting or linear lowering of the rear body mounting. Theguided downward pivoting is particularly facilitated by a horizontalpivoting bolt, to which the rear body mounting is releasably pre-lockedin the pre-alignment position to pivot the rear body mountingdownwardly. Guided linear lowering may be accomplished by a verticalaligning means, such as a guide rail or bolt, or any other guidingmechanism, to which the rear body mounting can be pre-locked in itspre-alignment position to be lowered in a guided fashion.

A separate lift mechanism or other type of auxiliary apparatus may beprovided to introduce a desired rear body mounting into the aligningcoupler. In order to install the rear body mounting on the base vehicle,the lift mechanism or other auxiliary apparatus is arranged to lift therear body mounting, which is parked outside the base vehicle, and tomove the rear body mounting into the aligning coupler. Such an auxiliaryapparatus may be independent of the base vehicle or may be incorporatedtherein. On the other hand, it is also possible to lift the rear of thevehicle to install the rear body mounting thereon.

The main coupler may be arranged in the form of a plurality of maincoupler sub-units disposed at a distance from each other such that theresulting main coupler force is transferred to the bottom structurealong the longitudinal axis of the base vehicle in the area of the rearaxle. Such an embodiment is provided particularly when the bottomstructure of the base vehicle comprises a carriage including twolongitudinal beams extending along opposite sides of the longitudinalaxis of the base vehicle to directly support the main coupler sub-units.In such cases, the bottom of the respective replaceable rear bodymounting accordingly comprises a plurality of mating couplers in anarrangement complementary to the main coupler sub-units.

In this case, the coupler joint for coupling a semi-trailer may comprisean intermediate frame supported on the main coupler sub-units such as totransfer both vertical loads and horizontal pulling or trailing forces.

According to the invention it is also possible to arrange the maincoupler in the form of several main coupler sub-units, a plurality ofwhich are disposed symmetrically with respect to the longitudinal axisof the base vehicle at a distance from each other, while a central maincoupler unit is located in the longitudinal axis of the base vehicle inthe area of the rear axle thereof. Owing to this arrangement, the forcesto be transferred to the bottom structure can be distributed over thebottom structure. In this embodiment, the central main coupler unit maybe dedicated to the support of a semi-trailer such as to transfer bothvertical loads and horizontal pulling forces.

For the majority of applications, the entire main coupler is arranged inthe form of a main coupler unit disposed in the longitudinal axis of thebase vehicle in the area of the rear axle. The main coupler may bedisplaced from the rear axle by 300 mm toward the front or rear end.Preferably, the amount of displacement is selected such as to favour astable driving state of the combined base vehicle and semi-trailer unit.

For the rest, the main coupler according to the invention may comprise apositive locking device, in particular including clamping members thatcan be set manually and/or through an actuator to positively engage orclamp the mating coupler fixed to the bottom of the respective rear bodymounting. Preferably, the main coupler is designed such that the matingcoupler and the rear body mounting are tightened vertically to thebottom structure when the mating coupler is being locked, and has beenlocked, in the main coupler. To meet this purpose, the mating couplermay comprise a ball pin or mushroom pin or any other wedge faces adaptedto be engaged by the clamping members of the main coupler in order tovertically tighten the mating coupler and, thus, the rear body mounting.

Further, the main coupler preferably comprises a centering guide tocentre and guide the mating coupler of the rear body mounting caught inthe main coupler while the rear body mounting is being lowered. Thecentering guide compensates for any deviation of the rear body mountingfrom its desired pre-alignment position. In order to avoid the rear bodymounting being distorted laterally and/or longitudinally in the aligningcoupler when the rear body mounting is inserted in the main coupler, thealigning coupler may be arranged to yield in a limited resilient fashionto compensate for any such distortions. Such limited resilience and/orsupport of the aligning coupler is provided in particular in the eventthat the aligning coupler is supported on the body of the base vehicleso that such distortions of the rear body mounting are kept away fromthe body of the base vehicle.

The clamping members of the main coupler may be constituted by clampingjaws that are displaceable linearly and/or pivotable. However, it isalso possible for the main coupler to be provided with a clamping memberin the form of a rotatable screw socket, or threaded tube, adapted to beengaged by a screw bolt embodying the mating coupler of the rear bodymounting. In this arrangement, the screw socket may be provided with aworm gear adapted to be engaged by a worm drive.

The adjustable clamping members of the main coupler may be controlled bya drive actuator, which may be embodied by a pneumatic, hydraulic orelectric actuator. Alternatively, or preferably additionally, theclamping members may be designed to be actuable manually.

In the following, the invention will be explained with reference toembodiments illustrated at least schematically in the drawing figures.

FIGS. 1 to 4 show embodiments of a powered road vehicle according to theinvention, including some detailed views illustrating how thereplaceable rear body mounting is supported and locked on the basevehicle.

FIGS. 5 to 8 show further exemplary road vehicles according to theinvention.

FIGS. 9 to 14 schematically show selected designs of base vehicle maincouplers for the replaceable rear body mountings in accordance with theinvention.

An exemplary embodiment of a powered road vehicle according to theinvention is illustrated in FIG. 1.

The base vehicle 1 comprises a load-transferring bottom structure 11 inthe form of a self-supporting vehicle body bottom 12. A front axle 14and a rear axle 15 are suspended from the bottom structure 11, and avehicle body 16 is supported on the bottom structure 11. The rear end ofvehicle body 16 is provided with side walls 17. The variable rear bodymounting 2 associated with base vehicle 1 is mounted in an easilyreleasable manner on base vehicle 1. When the variable rear bodymounting 2 is to be fitted on base vehicle 1, the rear body mounting 2is first aligned with respect to base vehicle 1 through one or severalaligning couplers 4, then guided and centered, and finally fixed oncethe rear body mounting 2 has passed to its predetermined final position.The aligning couplers 4 are arranged between base vehicle 1 and variablerear body mounting 2, while mating alignment elements 41 correspondingto the aligning coupler units 4 are firmly attached to the rear bodymounting 2.

When the centering process has been completed and the rear body mountinghas been fixed in its final position, the variable rear body mounting 2is lowered toward base vehicle 1 until the rear body mounting 2 can befastened to bottom structure 11 of base vehicle 1 by means of areleasable main coupler 3. A mating coupler 31 firmly secured to thevariable rear body mounting 2 is locked in the releasable main coupler3.

The locking connection established by means of main coupler 3 provides arobust link between base vehicle 1 and variable rear body mounting 2directly through the bottom structure 11 of base vehicle 1.

The main advantages of this solution according to the invention residein that it is applicable to light categories of powered road vehicles tobe equipped with rear body mountings, such as cars and light commercialvehicles. It is particularly advantageous that the static and dynamicforces from the variable rear body mounting 2 are transferred directlyto the bottom structure 11 of base vehicle 1; thus, the body 16 of basevehicle 1 is loaded only by relatively small forces from the aligningcoupler units 4, and since the substantially bigger static and dynamicforces from the variable rear body mounting 2 are transferred to thelower bottom structure 11 of base vehicle 1, it is considerably easierto influence the driving characteristics by design measures.

Preferably, the solution according to the invention provides for acentral releasable main coupler 3 in direct vicinity above the rear axle15 of base vehicle 1, and for an aligning coupler unit 4 in the centreof the roof area of base vehicle 1 at the gap towards the variable rearbody mounting 2. However, depending on the particular application, itmay be desirable to provide a plurality of aligning coupler units 4. Insome cases, for example, a superior design may be achieved by theprovision of two aligning coupler units 4, about which the variable rearbody mounting 2 may be pivoted downwardly once it has been alignedtherein. If heavier variable rear body mountings 2 are employed, it maybe necessary to use an auxiliary apparatus 9, such as a portal frame ormanipulator, to lift and convey the variable rear body mounting 2 (whenthe latter is separate from base vehicle 1) and to align it in thelongitudinal, transverse and vertical directions for assembly on, ordisassembly from, the base vehicle 1, which considerably facilitatesworking with a single aligning coupler unit 4.

FIG. 2 represents a preferred embodiment of the releasable main coupler3, and FIG. 3 illustrates a preferred embodiment of the aligning couplerunit 4.

When the variable rear body mounting 2 is to be placed on the vehiclebody 16, the rear body mounting 2 is first aligned with the aligningcoupler 4 fixed to the base vehicle 1, the aligning operation beingperformed with the help of the mating member 24 firmly secured to thevariable rear body mounting 2. If the variable rear body mounting 2 islight, it can be placed manually; heavier rear body mountings 2 may beplaced with the help of an auxiliary apparatus 9, such as a portal craneor movable frame.

When the front end of mating member 24 has been inserted in the aligningcoupler 4, the variable rear body mounting 2 is moved towards aligningcoupler 4 until the mating member 24 has reached its final positionwithin aligning coupler 4. In a preferred embodiment, the final positionis determined by a sensor 61, e.g. a contactless proximity switch, thatcauses the aligning coupler 4 to be locked by an actuator 62, e.g. apneumatic cylinder, when the variable rear body mounting 2 reaches itsfinal position within aligning coupler unit 4.

The locked condition, which at the same time secures the variable rearbody mounting 2 to the base vehicle 1, may be ensured, in one exemplaryembodiment, by a locking device 42, e.g. a bolt, attached to theactuator 62, said bolt being pushed by actuator 62 perpendicularly tothe driving direction and horizontally into coaxial bores arranged inmating member 24 and aligning coupler 4, respectively, in response to asignal from sensor 61.

Unlocking and removal of the variable rear body mounting 2 from thealigning coupler 4 is carried out in the inverse order of steps inresponse to an external signal, generated through an unlocking button,for example. When the variable rear body mounting 2 is held in thealigning coupler 4 (by the locking device 42 extending through aligningcoupler 4 and mating member 24), the variable rear body mounting 2 islowered relative to base vehicle 1. This may be performed either bylowering the variable rear body mounting 2, or by lifting the basevehicle 1. If the rear body mounting 2 is light, it may be lowereddirectly manually, while heavy rear body mountings may be held by anauxiliary apparatus 9. The alternative technique of lifting the basevehicle 1 may be realised passively by a floor-based platform lift, oractively by actuators 63 arranged at the rear axle 15 of base vehicle 1.

Once the variable rear body mounting 2 has been pivoted completelydownwards relative to base vehicle 1, the variable rear body mounting 2is locked in the releasable main coupler 3 arranged at the bottomstructure 11 of base vehicle 1. This locking condition may be achievedwith the help of a mating coupler 31 firmly attached to the variablerear body mounting 2; when the variable rear body mounting 2 is lowered,the mating coupler 31 enters a clamping main coupler 3 adapted to beopened and locked.

When the variable rear body mounting 2 is lowered, the clamping maincoupler 3 is open, and it is locked preferably automatically as soon asthe variable rear body mounting 2 has reached its final positionrelative to base vehicle 1. Locking of the main coupler 3 is preferablycontrolled by two sensors 64 arranged to sense the final position of thevariable rear body mounting 2 relative to base vehicle 1. When the rearbody mounting 2 reaches its final position, the sensors 64 activate anactuator 65 associated with the displaceable part of main coupler 3 tocause said displaceable part to pass into its locking position, in whichthe mating coupler 31 of the variable rear body mounting 2 is clamped inthe main coupler 3 arranged on the bottom structure 11 of base vehicle1.

The main coupler 3 is preferably opened in response to an externalsignal, whereupon the variable rear body mounting 2 can be liftedrelative to base vehicle 1.

In variations of the variable rear body mounting 2 that are intended toform a closed unit with the base vehicle 1 after installation thereon,the upper edges of the lateral side walls 17 of body 16 of base vehicle1 require sealings 26 in the area of the shoulders 23 of the variablerear body mounting 2. In a preferred embodiment of the invention, whenthe variable rear body mounting 2 is lowered relative to base vehicle 1and fixed in the aligning coupler 4 of base vehicle 1 by locking device42, the sealing 26 is compressed between the shoulder 23 of the variablerear body mounting 2 and the upper edge of vehicle body 16, said edgeand shoulder 23 being parallel to each other when the variable rear bodymounting 2 has been lowered to its final position.

FIG. 4 illustrates a possible way of providing additional support toheavy variable rear body mountings 2, supplementing the releasable maincoupler 3. The arrangement shown provides passive support members in theform of blocks 27 arranged on rear body mounting 2 and having limitedresilience or slight elasticity to bias the variable rear body mounting2, through main coupler 3, with respect to the bottom structure 11 inorder to reduce rolling motions of heavy rear body mountings 2.

FIG. 5 shows an embodiment of a powered road vehicle according to theinvention comprising a base vehicle 1 and a substitutable, box-like rearbody mounting 2. The rear part of body 16 of base vehicle 1 includesside and rear walls 17, 18. The lateral side walls 17 may join the frontpart of vehicle body 16, which includes the cabin, through transitionportions 17A. The rear body mounting 2 comprises a bottom part 21 to befitted between the side and rear walls 17, 18 and the transitionportions 17A, and shoulders 23 that are slightly seated on the free edgefaces of the lateral side walls 17 of base vehicle 1, or separated fromsaid edge faces by a narrow gap, when the rear body mounting 2 has beenplaced on base vehicle 1 and when the mating coupler 31 (mushroom-shapedin the embodiment shown) arranged on the bottom face 22 of rear bodymounting 2 has been locked in the main coupler (not shown in FIG. 5)provided above rear axle 15.

A protruding mating member 24 is firmly fixed to the upper end of frontwall 28 of the rear body mounting 2 having the shape of a box orcontainer, said mating member 24 being designed for aligning cooperationwith the aligning coupler (not shown in FIG. 5) arranged in the upperpart of body 16 of base vehicle 1. To place rear body mounting 2 on thebottom structure (not shown in FIG. 5) of base vehicle 1, an auxiliaryapparatus 9 in the form of a portal frame or manipulator may be used.

FIGS. 6 and 6A show a powered road vehicle according to the inventioncomprising a base vehicle 1 and a box-shaped rear body mounting 2. Thebase vehicle comprises a front axle 14, a rear axle 15 and a vehiclebody 16, the front part of vehicle body 16 including a driver's cab andthe rear part of vehicle body 16 having lateral side walls 17 and a rearwall 18. The rear wall 18 is arranged in the form of a rear door havingtwo door leaves 19 that are curved around the rear corners of basevehicle 1 to join the lateral side walls 17. The rear body mounting 2has a bottom part 21 to be fitted between the side and rear walls 17,18, and shoulders 23 conforming to the upper edge faces of the side andrear walls 17, 18.

FIGS. 6 and 6A further show an aligning coupler 4 arranged in the rearwall of the driver's cab formed by vehicle body 16. In this embodiment,the aligning coupler 4 comprises an alignment portion 41 which is opentowards the top and rear sides and is shaped as an alignment mouthtapering towards the front at both lateral sides such as to define ahollow wedge. When the rear body mounting 2 is lifted and movedforwardly from the rear side, a mating member 24 complementary to thealignment mouth and secured to the front wall of rear body mounting 2can be inserted in the alignment portion 41, thus aligning the rear bodymounting 2 horizontally. Further, the aligning coupler 4 is provided atits centre with a vertical guide member 43 in the form of a guide pinprotruding vertically upwardly and having a conically tapering free end.The guide pin cooperates with the mating member 24 of rear body mounting2 such that the rear body mounting 2 can be lowered while being guidedin a linear, or translational, manner until the rear body mounting 2 isseated on the main coupler (not shown here).

An aligning coupler 4B of the aforementioned type, e.g. including apin-shaped guide member 43', may be arranged additionally oralternatively at the rear end of base vehicle 1. It is also possible toprovide two or more aligning couplers 4, 4B of this type arranged sideby side at a distance from each other such as to cooperate with acorresponding plurality of mating couplers formed on the rear bodymounting 2.

FIGS. 7 and 7A depict rear views of a powered road vehicle according tothe invention. In this embodiment, the load-transferring bottomstructure 11 comprises a vehicle body bottom 12 in the form of bottomplate, and a carriage 13 on which the main coupler is arranged in theform of main coupler sub-units 3A, 3B such that the resulting maincoupler force is transferred to rear axle 15 along the longitudinal axisL of base vehicle 1. The mating couplers 31 of the box-like rear bodymounting 2 are releasably locked in the main coupler sub-units 3A, 3B,and the rear body mounting 2 is additionally supported on the bottomplate of the vehicle body bottom 12 by support blocks 27.

The rear body mounting 2 further comprises shoulders 23 extending acrossthe lateral side walls 17 at a slight distance. As illustratedschematically in FIG. 6, the rear wall 18 is arranged as a door havingtwo leaves 19 which are curved around the rear corners of base vehicle 1to join the lateral side walls 17, where the door leaves 19 are hingedon the lateral side walls 17 or on a separate support (not shown). Owingto this construction, the entire width of base vehicle 1 between thelateral side walls is available when inserting the rear body mounting 2from the rear end of the vehicle.

FIG. 8 shows a powered road vehicle according to the invention includinga semi-trailer 5 coupled to the main coupler (not shown) of basevehicle 1. A replaceable rear body mounting 2 may be locked in the maincoupler instead of the semi-trailer 5. Such a replaceable rear bodymounting 2 is represented in dashed lines and may have the shape of avertically extending container. Thus, the main coupler according to theinvention (not shown in FIG. 8) is designed such that, on the one hand,an adapted replaceable rear body mounting 2 can be locked to theload-transferring bottom structure 11 and, hence, to the suspended frontand rear axles 14, 15 of base vehicle 1, and on the other hand, asemi-trailer 5 can be coupled to the bottom structure 11 such as totransfer vertical loads and horizontal pulling or trailing forces. Thecoupler joint (not shown) of the semi-trailer 5 forms part of thesemi-trailer coupler SA. FIG. 9 schematically shows an example of such asemi-trailer coupler.

FIG. 9 schematically illustrates a main coupler 3 according to theinvention comprising a clamping jaw 32A secured to the bottom structure11 of the base vehicle (not shown), and a clamping jaw 32B which isdisplaceable through an actuator, e.g. a hydraulic actuator, in thedirections indicated by the double arrow. The semi-trailer coupler 5A ofthe semi-trailer 5 is associated with a ball pin 51 fixed to thesemi-trailer 5, the ball of pin 51 being engaged in a ball socket 52such as to be movable to all sides in a sliding manner, the ball socket52 being locked between the clamping jaws 32A, 32B of the main coupler 3through a mushroom-shaped coupling rod 53. Hence, both the verticaltrailer load F and the horizontal pulling forces Z exerted by thesemi-trailer 5 are transferred to the bottom structure 11 of the basevehicle through the ball pin 51, the ball socket 52, the mushroom-shapedcoupling rod 53, and the main coupler 3.

The bottom faces of rear body mountings according to the invention (notshown) are each provided with a mating coupler 31 corresponding to themushroom-shaped coupling rod 53 to releasably lock the respective rearbody mounting between the clamping jaws 32A, 32B of the main coupler 3.The mating coupler 31 is discus-shaped and comprises upper and lowerannular conical clamping surfaces 32D engaged by the complementaryclamping mouths of the clamping jaws 32A, 32B.

As indicated by the double arrow depicted in dashed lines, the clampingjaw shown on the right-hand side in FIG. 9 may likewise be displaceablein two directions by an actuator. Further, as represented by thetrailing force component Z, the clamping jaws 32 opposing each otherdiametrically across the mating coupler 31 (53) may face each other in adirection transverse to the driving direction of the vehicle. Thisarrangement is favourable particularly when the mating coupler 31 of arear body mounting (not shown here) is pivotable downwardly from thepre-alignment position to the final position against the drivingdirection so that the mating coupler 31 can pivoted between the openedclamping jaws 32 perpendicularly to the plane of the drawing figure.This shortens the opening path of the clamping jaws 32B as compared to asituation where the mating coupler 31 is pivoted between the jaws alonga trajectory comprised in the drawing plane of FIG. 9.

FIG. 10 schematically shows an embodiment of the main coupler 3 when thelatter is designed as a ball-clamping coupler. The main coupler 3comprises a coupler block 33 fixed to the load-transferring bottomstructure 11 of the base vehicle such as to transfer forces. A fixedclamping jaw 32A and a displaceable clamping jaw 32B, which may bedisplaceable hydraulically, are arranged in the coupler block 33, bothclamping jaws being formed as ball sockets. The mating coupler 31attached on the bottom face of rear body mounting 2 is designed as aball pin, the spherical head of which is clamped between the clampingjaws 32A, 32B to prevent linear and rotational movement of the ball pin.The upper part of coupler block 33 is provided with a centering guideportion 33A in the form of a hollow centering cone to guide the matingcoupler 31 of the rear body mounting 2 between the clamping jaws 32A,32B when the coupler 31 of the rear body mounting is lowered into themain coupler 3.

The displaceable clamping jaw 32B is guided displaceably in a guideblock 34, which in turn is secured to coupler block 33 such as to bedisplaceable longitudinally. In addition, the displaceable clamping jaw32B is supported by guide block 34 through a biasing spring 35 extendingin the direction of displacement. This arrangement allows the matingcoupler 31 to be snapped into the main coupler 3 in a resilient manner;to this end, the displaceable clamping jaw 32B--just like the fixedclamping jaw 32A--also has an oblique guiding surface 37 to guide thespherical head of the mating coupler 31 between the clamping jaws 32A,32B; in so doing, the mobile clamping jaw 32B is first pushed away andthen urged back by spring 35 once the spherical head of the coupler 31has snapped into the ball sockets formed by the clamping jaws. A lockingmember 36, represented by a bolt in FIG. 10, may be set manually and/orby an actuator to lock the mobile clamping jaw 32B in its clampingposition.

In this embodiment of the main coupler, the trailer coupler of thesemi-trailer (not shown) likewise comprises a spherical coupling rod,instead of the mushroom-shaped coupling rod 53 in FIG. 9.

In the embodiment shown schematically in FIGS. 11 and 11A, the rear bodymounting (not shown) is also locked in main coupler 3 through a ball pinserving as the mating coupler 31. The coupler block 33 secured to thebottom structure 11 is shaped as a semi-spherical socket; twodisplaceable arcuate clamping jaws 32B opposing each other protrude intothe hollow cylindrical insertion section of the semi-spherical socketsuch as to engage and clamp the neck portion of the spherical head ofmating coupler 31. This causes the mating coupler 31 to be drawndownwardly into coupler block 33 and clamped horizontally on all sides.

The displaceable clamping jaws 32B are supported by biasing springs 35arranged within coupler block 33; in the present embodiment, thesesprings are provided in the form of annular springs or hairpin springsor leaf springs. The clamping parts of the jaws 32B protruding into thehollow cylindrical insertion section of the semi-spherical socket ofcoupler block 33 are provided with oblique centering and guidingsurfaces 37 engaged by the spherical head of mating coupler 31 when thelatter is lowered into the main coupler such that the clamping jaws 32Bare urged away from each other against the resilient force of thebiasing springs 35, and the spherical head is caught between theclamping jaws.

Moreover, the clamping jaws 32B may be locked in the clamping positionwith the help of locking members 36, e.g. transversely extending bolts,guided displaceably in associated guide bores within coupler block 33and supported on a locking bridge 38, which is adjustable manuallyand/or by an actuator in the directions indicated by the double arrow.

According to FIG. 12, the main coupler 3 is arranged in the form of ascrew coupler, in which a mating coupler 31 fixed to the bottom of rearbody mounting 2 is formed as a screw pin that is drawn into a rotatablethreaded tube 39. The threaded tube 39 is supported rotatably onbearings 39A provided in the coupler block 33 of main coupler 3 which inturn is secured to the bottom structure 11 of the base vehicle. The freeend of threaded tube 39 provides a hollow conical centering guideportion 33A adapted to centre and guide a complementary cone formed onthe free end of mating coupler 31 of rear body mounting 2 into thethreaded tube 39.

The outer circumference of the threaded tube 39 may be formed as a wormpinion engaged by a drive worm 39B that may be driven manually and/or bya motor drive 39C. A displaceable locking bolt 36 is supported in aneccentric position at the bottom of the threaded bore of tube 39 and canbe inserted in a locking bore provided in the mating coupler 31 to lockthe mating coupler in the coupled state thereof. To avoid the matingcoupler 31 penetrating too deeply into main coupler 3, the motor drive39C may be switched off in the event of an overload; in addition, aposition sensor 61 may be provided to stop the motor drive 39C.

The main coupler shown in FIG. 13 is designed in the form of ascissor-type clamping mechanism comprising claw-like clamping members32C which cooperate in a clamping manner with a mating coupler 31 or 53(cylindrical in the embodiment shown) of the rear body mounting (notshown) or the semi-trailer coupler (not shown), respectively. The matingcoupler 31 or 53 may comprise a groove (not shown) engaged by theclamping claws 32C in a clamping manner, and the clamping claws 32C mayadditionally exert a vertical downward force component. It is alsopossible to design the mating coupler 31 or 53 in the form of a mushroompin or ball pin, and to adapt the shape of the clamping claws 32C to theshape of such a pin.

The clamping claws 32C comprise actuating arms 72 and are pivotabletherewith about a stationary central pivot pin 71. A drive gear 70engages the actuating arms 72 to close or open the claws 32C to clamp orrelease the mating coupler 31. Instead of the mechanical drive gear 70illustrated in the exemplary embodiment, a hydraulic or pneumatic drivearrangement may be provided in which hydraulic or pneumatic cylindersdirectly engage the actuating arms 72.

In the embodiment shown, drive means 39C rotate a central drive pinion77 to operate two driven elements 73 which are embodied by lead screwshaving opposite threads. The driven elements 73 engage the free ends ofthe actuating arms 72; in the embodiment shown, ball nuts 74 are mountedon the driven elements 73 to be displaceable in opposite directions, theball nuts 74 engaging ball cups of the actuating arms 72.

As any movement of the actuating arms 72 necessarily results in adisplacement of the driven elements 73, the whole drive gear 70 ismounted on a slide 75 displaceable in longitudinal guides. The displacedpositions of various components are depicted in dashed lines in FIG. 13and denoted by reference numerals including an apostrophe.

If a hydraulic or pneumatic drive is used, the actuating arms 72 orclaws 32C in addition have to be locked mechanically (not shown) in theclamped position to ensure safety in the event of a fluid pressure drop.

Auxiliary supports 78 may be provided for the claws 32C to give theclaws 32C further support in the clamped position. Such auxiliarysupports 78 may be designed such as to simultaneously fulfil thefunction of an additional mechanical lock of the claws 32C in theirclamped position when a hydraulic or pneumatic drive is utilised.

A centering guide portion 33A may be arranged in front of the clampingclaws 32C to guide the mating coupler 31 into the clamping claws 32Cwhen the rear body mounting is pivoted downwards.

FIG. 14 schematically shows an embodiment of a main coupler comprising aplurality of main coupler sub-units 3A, 3B supported at a distance fromeach other on a carriage 13 constituting the load-transferring bottomstructure of the base vehicle, said main coupler sub-units 3A, 3B beingarranged to transfer vertical loads and horizontal trailing forces. Inthe embodiment shown, the sub-units 3A, 3B (only one sub-unit beingrepresented in FIG. 14) comprise funnel-shaped coupler sockets 30engaged by conical mating couplers 31A fixed to the bottom of rear bodymounting 2. Each mating coupler 31A further comprises a locking pin 31Bthat vertically downwardly engages an associated bore in the respectivesub-unit; the locking pin 31B is engaged by a clamping wedge 32Esupported on carriage 13 and displaceable by an actuator.

By means of the clamping wedges 32E, the mating couplers 31A of rearbody mounting 2 are pulled down towards the carriage 13 and lockedthereto. The coupler sockets 30 are coated with wear layers 30A; thetightening forces transferred from the clamping wedges 32E to the matingcouplers 31A are transferred to the coupler sockets 30 through the wearlayers 30A.

It will be appreciated that various additions and modifications may bemade to the embodiments shown and described.

In the embodiments according to FIGS. 10 and 11, for example, thedisplaceable clamping jaw may be designed to be releasable manually orby an actuator against the force of the biasing spring 35 when themating coupler is to be uncoupled.

Further, in the event that a mere clamping lock is not sufficient toprevent the rear body mounting from rotating, additional lockingprojections or the like may be provided to positively prevent anyrotation.

Moreover, the mating coupler arranged on the bottom of the rear bodymounting may be designed to be lowered or pivoted downwards manually orby an actuator; in this arrangement, it may be possible first to lowerthe rear body mounting to its final position and then to lower themating coupler into the main coupler to lock the mating coupler in themain coupler.

In contrast to the embodiments shown, it is also possible in principleto provide the main coupler mechanism at the bottom of the rear bodymounting, and the mating coupler on the bottom structure, even thoughsuch an arrangement may be more complicated and/or costly.

The side walls provided on the rear part of the powered road vehicleaccording to the invention may be arranged to be detachable or pivotabledownwards.

What is claimed is:
 1. A powered road vehicle of the type of a passengercar having a permissible maximum laden weight of 3.5 tons or of a lorryhaving a permissible maximum laden weight of 5 tons, comprising:a basevehicle having a load-transferring bottom structure which includes avehicle body bottom and/or a carriage, said bottom structure beingprovided with a front axle and at least one rear axle, the base vehiclefurther including a vehicle body supported on the bottom structure, therear part of the vehicle body having side walls, a replaceable rear bodymounting upwardly joining the side walls, the rear body mounting beingsupported directly on the bottom structure in a load-transferringmanner, the base vehicle further comprising a main coupler directlymounted and arranged at the bottom structure in a load-transferringmanner, and an aligning coupler separately arranged at a distance fromthe main coupler, the rear body mounting further comprising a matingcoupler mating with the main coupler of the base vehicle and a matingmember mating with the separate aligning coupler of the base vehicle,said rear body mounting, in a locking position, being releasably lockedin the main coupler of the base vehicle by mating engagement of themating coupler and the main coupler, said mating member of said rearbody mounting being adapted to engage with the aligning coupler in apre-alignment position, and to be lowered from the pre-alignmentposition into the locking position at which the main coupler is lockedto the mating coupler, said main coupler being arranged and designedboth to provide positive engagement of the rear body mounting such as toprevent displacement and rotation thereof, and to enable coupling of asemi-trailer with the bottom structure such that vertical loads andtrailing forces resulting from the coupling with the semi-trailer aretransferred by the main coupler to the bottom structure.
 2. The poweredroad vehicle according to claim 1, wherein at least one additional rearbody mounting substitutable for said rear body mounting is provided andarranged to be supported directly on the bottom structure in aload-transferring manner, the additional rear body mounting having amating coupler and a mating member which are, respectively, releasablylockable to the main coupler and attachable to the aligning coupler. 3.The powered road vehicle according to claim 2, wherein the main couplercomprises a central main coupler unit arranged in the longitudinal axisof the base vehicle in the area of the rear axle.
 4. The powered roadvehicle according to claim 2, wherein each of the rear body mountingshave a bottom part which fits between the side walls, the bottom parthaving a bottom wall adapted to lock the rear body mounting to the maincoupler.
 5. The powered road vehicle according to claim 4, wherein themain coupler comprises a central main coupler unit arranged in thelongitudinal axis of the base vehicle in the area of the rear axle. 6.The powered road vehicle according to claim 4, wherein at least one ofthe rear body mountings is provided with shoulders adapted to be seatedon the side walls.
 7. The powered road vehicle according to claim 6,wherein the main coupler comprises a central main coupler unit arrangedin the longitudinal axis of the base vehicle in the area of the rearaxle.
 8. The powered road vehicle according to claim 1, wherein the sidewall of the vehicle includes a rear side wall and lateral side walls,said rear side wall of the base vehicle being arranged in the form of apivotable door having two door leaves pivotable about hinges disposed inthe area of the lateral side walls at a distance from rear ends of thelateral side walls.
 9. The powered road vehicle according to claim 8,wherein the main coupler comprises a central main coupler unit arrangedin the longitudinal axis of the base vehicle in the area of the rearaxle.
 10. The powered road vehicle according to claim 1, wherein thealigning coupler is arranged in the form of a plurality of aligningcoupler sub-units disposed at a distance from each other on the vehiclebody of the base vehicle and/or on the bottom structure thereof.
 11. Thepowered road vehicle according to claim 10, wherein the main couplercomprises a central main coupler unit arranged in the longitudinal axisof the base vehicle in the area of the rear axle.
 12. The powered roadvehicle according to claim 10, wherein the aligning coupler comprises atleast one horizontally extending alignment element arranged at adistance above the main coupler, the mating member of the rear bodymounting being adapted to be inserted horizontally in the alignmentelement, the aligning coupler further comprising a locking deviceincluding a horizontally displaceable bolt adapted to releasably lockthe rear body mounting in the pre-alignment position such that the rearbody mounting can be pivoted downwards into locking engagement in themain coupler.
 13. The powered road vehicle according to claim 12,wherein the main coupler comprises a central main coupler unit arrangedin the longitudinal axis of the base vehicle in the area of the rearaxle.
 14. The powered road vehicle according to claim 10, wherein thealigning coupler comprises a horizontal or vertical alignment elementinto which a mating member of the rear body mounting can be introducedhorizontally or vertically, respectively, and vertical guiding meansalong which the rear body mounting can be lowered in a linear verticalmovement.
 15. The powered road vehicle according to claim 14, whereinthe main coupler comprises a central main coupler unit arranged in thelongitudinal axis of the base vehicle in the area of the rear axle. 16.The powered road vehicle according to claim 1, wherein the main coupleris arranged in the form of a plurality of main coupler sub-unitsdisposed at a distance from each other such that the resulting maincoupler force is transferred to the bottom structure in the longitudinalaxis of the base vehicle in the area of the rear axle.
 17. The poweredroad vehicle according to claim 16, wherein the main coupler comprises acentral main coupler unit arranged in the longitudinal axis of the basevehicle in the area of the rear axle.
 18. The powered road vehicleaccording to claim 1, wherein any vertical supporting of the rear bodymounting on the vehicle body of the base vehicle is exclusively realizedby resilient means.
 19. The powered road vehicle according to claim 1,wherein the main coupler comprises a centering guide portion whichcenters and guides the mating coupler of the rear body mounting when therear body mounting is lowered to lock the mating coupler in the maincoupler, and the aligning coupler and/or its associated support meansare arranged to have limited compressibility.
 20. The powered roadvehicle according to claim 1, wherein the main coupler comprises acentral main coupler unit arranged in the longitudinal axis of the basevehicle in the area of the rear axle.
 21. The powered road vehicleaccording to claim 20, wherein the central main coupler comprisesdisplaceable clamping means adapted to lock the rear body mounting tothe bottom structure such that the rear body mounting is tightenedvertically to the bottom structure and prevented from displacement androtation, the rear body mounting being supported on the bottom structureby additional support means.
 22. The powered road vehicle according toclaim 20, wherein the central main coupler is arranged in the form of aresilient snap-in coupler having at least one resiliently yieldingclamping means adapted to cooperate in a clamping manner with a matingcoupler fixed to the bottom of the rear body mounting, the clampingmeans being further lockable by a locking means.
 23. The powered roadvehicle according to claim 20, wherein the central main coupler isprovided with a drive means.
 24. The powered road vehicle according toclaim 23, wherein the central main coupler and the mating coupler lockedtherein comprise cooperating conical clamping surfaces.
 25. The poweredroad vehicle according to claim 23, wherein the central main couplercomprises clamping elements opposing each other diametrically of themain coupler, each clamping element being displaceable by an actuator.26. The powered road vehicle according to claim 25, wherein thedisplaceable clamping elements oppose each other transversely to thedriving direction.